Charging Communication with ISO 15118 (July 2022)

5th Internat. ISO/IEC 15118 Testing Symposium in South Korea | Work on Edition 2 in Rome

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The ISO/IEC 15118 Testing Symposium initiative now invites you to the "5th International ISO/IEC 15118 Interoperability and Conformance Testing Symposium", which will be held on 10 and 11 November in South Korea on the island of Jeju-do. Host of the event will be the Korea Smart Grid Institute (KSGI). In a three-day face-to-face meeting from 7 to 9 November, the project groups meet in the same place in order to further hone the Edition 2 of ISO 15118.

Registration to attend this event is possible until September 23, using the questionnaire of TU Dortmund, which is acting as an organiser among other things. Further information about the Testing Symposium itself, including the official news and invitation can be found under http://www.testing-symposium.net.

I will also be back on site and testing my open source implementation RISE V2G (GitHub) for compatibility with other implementations and conformance to the standard, as well as working on edition 2 in advance. In addition to the test systems made available as usual by the TU Dortmund and Vector Informatik that have been implemented according to ISO 15118-4 and ISO 15118-5, thus making the conformity tests easier, many companies from the USA, Europe and Asia will certainly be present once again.

For this Testing Symposium, I expect (or I hope for) more implementations, which will finally also enable secure communication via TLS and therefore Plug & Charge authentication and authorisation using digital certificates and signature verification.

As already mentioned, the use cases (ISO 15118-1) as well as the technical requirements (ISO 15118-2 and -8) will be further developed within the framework of an edition 2 of ISO 15118 during the three days preceding the test event. In my blog post of 13 April, I already mentioned the issues that will be the subject of processing for edition 2. Currently, a good 1,000 comments for ISO 15118-2 have been submitted for revision. Now these must be processed in regular phone conferences and web meetings to reach a consensus on a solution in each case. This may well drag on for a while, as the experience of the past weeks and months shows.

For this reason there was another face-to-face meeting in Rome last week, from 11 to 15 September, to focus on processing issues. I was also present here and ... have to say with a little disappointment that we have not progressed as quickly as hoped. Certain thematic blocks, such as the reverse energy flow (to enable bi-directional energy flow), especially with alternating current charging, where the inverter sits in the car and not in the stationary charging station (as in the case of the direct current charging), provoke controversial views and discussions which must first be solved together. The topic of wireless energy transfer, for which the relevant messages first have to be defined, also poses challenges for the standardisation community. This is because the basis on which the ISO 15118-2 must be based for wireless power transfer is the IEC 61980, which defines the WPT (wireless power transfer) for electric vehicles. But this document family is itself still under development, which requires a close cooperation between the two committees, so that current levels developments in IEC 61980 can be adopted at the same time in ISO 15118-2.
In the case of wireless energy transfer, for example, messages must be exchanged, which

guide the electric vehicle to the exact location of the primary coil (which is usually installed in the ground),
enable a communicative connection (coupling) between electric vehicle and the communication controller, which manages a lot of primary coils in, for example, a multi-storey car park (in technical jargon, SECC which stands for supply equipment communication controller),
perform a compatibility check between the primary coil installed and available in the ground and the secondary coil installed in the vehicle floor (here, incompatibilities seem to be present on the market due to different coil geometries, for example),
enable an efficiency verification (e.g. a minimum spacing and minimal overlap of the two coils must exist to allow a certain degree of efficiency of power transfer), and
enable constant monitoring for the purpose of detecting foreign objects between the two coils (coins, can, cat, etc.).

Edition 1 of the ISO 15118-2 is not a novel, which one delves into from time to time, and I fear edition 2 will not contribute much to the simplification. I won't give up hope, but just due to the fact that the bi-directional energy transfer and wireless power transfer/communication topics will be added to the existing document of over 350 pages, it is clear this will not exactly contribute to a smaller number of pages. Well, nothing will help, because the standard has to be made ready for the future, and it now looks like the charging chord will eventually slip into the background and the electric vehicle will be used sooner or later as an energy storage device.

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Marc Mültin

Marc, the Founder and CEO of Switch, has over 13 years of experience in the e-mobility space and holds a PhD in Computer Science. He is the leading global expert and co-author of international EV communication standards (ISO 15118 & OCPP 2.0.1) that underpin the Switch platform.

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Marc Mültin